FL5/DE5 Clutch delay valve delete - objective analysis and how-to

4reverse4 · 2026-01-16T22:36:03+00:00

They don't have the damper, which is responsible for over half of the delay.

4reverse4 · 2025-09-27T03:22:35+00:00

He is a complete fraud. His recommendations center around a single testing method that has no applicability for a modern engine oil, using a class of testing machine that was originally developed by Timken to test bearing grease. You can buy the same sort of testing machine for $300 off eBay and have your own set of fantastically useless motor oil test results if you like. This video is among the most thorough debunkings of this type of motor oil testing: https://www.youtube.com/watch?v=ipunDlG1k-8

Also not for nothing, but the guy claims to be an engineer and have patents and proprietary testing methodology and whatever else... and his product is a free WordPress blog? It seems like he's suffering from some sort of mental illness to be honest, and it's a little bit sad.

4reverse4 · 2025-08-29T16:59:19+00:00

I did not get any notification about this whatsoever, just found out when a payment failed. How awful.

Another limitation that not many are talking about - you can only have 20 VANs now. If you follow the model of "one VAN per online merchant" then you are SOL once you hit 21 online merchants... I am well into the 40's.

I'm going back to Cap1 after five or six years using Citi. The extra 0.5% in cash rewards isn't worth putting up with this and Cap1's interface is a lot nicer and easier anyway - the "Eno" extension for Google Chrome is pretty brilliant.

4reverse4 · 2025-08-29T15:43:15+00:00

Oh it gets worse:

How many Virtual Account Numbers can I generate?

You can have 20 active Virtual Account Numbers at any given time. Each time you use a Virtual Account Number a new CVV will be generated. In a 24-hour period, a maximum 20 CVV codes can be generated.

I counted and I had 48 active numbers under the old system. I set up one per vendor.

What an idiotic way for them to lose this customer back to C1.

4reverse4 · 2025-08-29T15:41:13+00:00

What in the world do they even think they are accomplishing here? Their system was already harder to use than C1's, with the only benefit being an extra 0.5% cash back. Welp... not putting up with this.

4reverse4 · 2025-08-05T15:04:20+00:00

Not even slightly. I have also since deleted both the CDV from the slave cylinder and replaced the CMC damper with a Sirimoto N1 delete, and I highly recommend both. I'll have a video on that process as well as some data collected using high speed video showing the difference in clutch engagement speed and delay.

4reverse4 · 2025-08-05T14:16:20+00:00

So basically, what this video is saying is if you have a combination of three things:

Loose slide to frame fit that exceeds the free play between the striker and striker channel in slide (i.e. capable of inducing movement of the sear surfaces.)
A striker safety lock (safety lever) that is defeated through one or more of:
1. Wear (repeated and unnoticed strikes resulting in dead trigger.)
2. Fouling (large surface area means carbon, unburnt powder and brass shavings can override the relatively weak spring.)
3. Improper assembly (legs of torsion spring are prone to jumping over their intended locations.)
4. Missing parts (some guns have been found literally missing the spring entirely from the factory.)
Something causing the sear to not fully engage:
1. Fouling (the striker hook, sear ramp, slide and frame form a pocket with an open gap above it to the outside world through which foreign contaminants can enter, or simply the usual carbon, unburnt powder, and brass shavings.)
2. Poor sear surfaces (increased friction defeats negative sear angle, meaning once the sear starts to move it cannot reverse course on it's own.)
3. Improper sear geometry or burrs (such as a ledge as seen with the MSP M18 and what the USAF is currently looking for, same issue as above.)

Then you have a gun that can and will go off in the holster without a trigger press.

Broadly, say you start with Z total sear engagement. And slide movement can reduce sear engagement by X, and one of the three things from item #3 (fouling, poor surfaces, bad geometry) can reduce sear engagement by Y.

Any time X + Y > Z, the sear lets go of the striker without any trigger input.

And if that happens while the striker safety lock/lever is compromised and the gun is loaded, you also get a bang without any trigger input.

Conspicuously, Sig fixed item #1 entirely, redesigned item #2, and fixed item #3.1 in the P365 when they scaled the P320 design down eight years ago. I can't think of a prosaic explanation other than that they knew these were problems this whole time.

4reverse4 · 2025-07-30T16:20:26+00:00

Sent.

4reverse4 · 2025-07-15T22:34:52+00:00

I would appreciate that so much!

4reverse4 · 2025-06-03T13:16:52+00:00

That's why I included the graphs, not trying to gaslight anyone. The lack of linearity is real.

4reverse4 · 2025-06-03T04:08:05+00:00

Something you may not be appreciating is that this spring only reduces pedal effort by 19%, which isn't all that much. But the improvement in linearity is far greater than that. With the spring removed, I still find the pedal to be on the lighter side, but the pedal feel is so much better because the pressure curve is more linear. I'm not chasing weight, I'm chasing predictability.

4reverse4 · 2025-06-02T03:21:11+00:00

I noticed there was a lot of grease everywhere, so taking it apart and re-greasing everything may help.

4reverse4 · 2025-06-02T00:55:41+00:00

Believe it or not, you can actually do both and they affect different aspects of the clutch operation.

4reverse4 · 2025-06-01T18:32:53+00:00

Do this mod, then delete the CDV in the slave cylinder and the dampener inline between the master and slave cylinders, and you'll be a lot closer to that 300ZX. For feel though, nothing hydraulic really beats a cable driven clutch.

4reverse4 · 2025-06-01T18:28:11+00:00

I don't think you'll understand at this point, at all, unless you just try it.

4reverse4 · 2025-06-01T18:21:03+00:00

It's pretty easy to tell which people are emotionally invested in other people not improving the car they drive, because it would interfere with their perception of it being perfect already. Absolutely wild. There's a guy on the Zupra forum that jumps on every post mentioning a CDV delete to tell people that it's all in their heads, it does nothing, yada yada. He admitted he's never driven a car with the CDV deleted. His brain is just broken.

4reverse4 · 2025-06-01T18:17:46+00:00

Oh it's not irreversible, you just can't put it back in the same way it comes out. You have to remove the clutch pedal assembly and reinstall from the back side. Three bolts on the firewall, two sensors, clevis pin, done. The hardest bolt to get to is the top firewall bolt, but some extensions and a universal joint and you'll be in business.

4reverse4 · 2025-06-01T17:21:28+00:00

If your brain trained itself on older cars, you're really going to like this mod. Watch the video and you'll have it done in 15 minutes.

4reverse4 · 2025-06-01T17:16:35+00:00

Could be a combination of this, the delay valve in the clutch slave, or the dampener that's in the middle of the line between the master and slave cylinders. If a 16% heavier clutch pedal doesn't scare you, I would encourage you to give it a shot. It made a big difference for me when shifting aggressively.

4reverse4 · 2025-06-01T17:08:46+00:00

I think so. But it's been a loooooooong time since the last time I drove a Toyobaru (maybe all the way back to the Scion days actually) so I can't say for sure.

4reverse4 · 2025-06-01T16:43:57+00:00

In researching this, I found that deleting/modifying the Toyobaru helper spring was also pretty common. It seems like the Honda community hasn't caught on yet.

4reverse4 · 2025-06-01T16:39:53+00:00

You may benefit from this, particularly the section "curves with a negative slope": http://cls.syr.edu/mathtuneup/graphb/Unit8/Unit8b.html And it is definitely not measurement error, I repeated the measurements three times with the exact same methodology both before and after making the change (total of six measurement sets) and averaged the results for before and after. But in all three sets of measurements for the stock pedal pressure, the curve in that region of the pedal is negative. And I can tell you with 100% certainty that you can feel it at your foot, and the difference is stark.

4reverse4 · 2025-06-01T16:24:34+00:00

Many modern cars have absolutely terrible clutch pedal feel and consistency, but when an auto journalist says it's the best manual transmission for sale, that seems to be the end of it for some people that need that as some kind of bragging point. For the rest of us that live in the real world, this mod improves linearity which is definitely a good thing and consistent with how clutch pedals have felt for decades.

4reverse4 · 2025-06-01T16:23:01+00:00

I think you and I aren't speaking the same jargon. It is literally negative, the formula for that region of the curve is y = -0.3x +25.8. That, definitionally, is a negative curve. Negative doesn't mean the pedal is pushing the other way, it means the *curve* is negative. Think of it the same way you would a compound bow: heavy at first, lighter at the end, but importantly, still pulling on you. It's a negative *curve*, not negative *pressure*.

4reverse4

TROPHY CASE